Hello
You can find example of .cfg files for MPC8xx in {Install}\PowerPC_EABI_Support\Initialization_Files\PQ1 (where {Install} refers to your installation directory).
You can find more information on commands you can use in the .cfg file in "{Install}\Help\PDF\Pro & Linux App Edition Targeting Manual.pdf" in chapter "Target Initialization File".
As stated there "A target initialization file is a file that contains commands that initialize registers, memory
locations, etc. on a target board."
CrasyCat